Hello everyone, new here and just got this 4Runner. The engine is the 3.0L
anyways had a high Nox. Reading was 1606, limit was 704.
The tech said I had an original cat and that could be it, he also said my timing was off he stated it was at 20 and possibly has a miss fire. I think it’s also worth mentioning the vehicle was from a higher altitude so could the idle also be high?

so my question is, will a new cat drop me to normal levels, just so I can register the car and get plates. If it can I will address the other issues later. Also is there anything else I can do?

 

Find a different tech to diagnose it correctly. Where are the HC and CO levels?. NOx is a byproduct of hot combustion and related to the EGR system. Timing also needs to come down first. Just reducing the timing will help as it is way too advanced.

 

Thankfully, we don't have smog testing where I live. Now OR where I lived before, in Yuma,, Az.

Having said that, I still have the original cat in my 87 pickup, and 99 4Runner. A little trick I was shown by some professional mechanics to keep the cat operating decently, is to take a rubber mallet, or ballpeen hammer, your choice, and bang on the cat for a bit. I do it ever couple years, at least I have on my pickup that I've owned since 88. I can't speak to the official test of the vehicle, but every time I beat the cat up good, it changes the scent of the exhaust dramatically. I definately notice a big difference.

In addition to setting the timing correctly, which you positively should do, try getting under the truck and beating the cat a bit to see what happens. I was told it breaks up the surface of the materiel in the cat, and makes it work ike it was much newer. Don't beat it enough to damage the outer shellof the cat, but certainly enough to bounce it around some. Can't hurt.

By the same token, these same mechanics told me the best thing you can do for a cat is to pull it out of the system, stick a big screwdriver down into it, and swirl it around hard. Then dump all the materiel into the trash, and put the cat back into the system. Once again, this was a place with no smog checks. You decide.

I wish you all the best!
Pat☺